Now that the space station's new robot is fully assembled, astronauts are preparing to attach the giant machine directly to the orbiting outpost for the first time on Tuesday.
Astronauts Richard Linnehan and Robert Behnken went on a space walk Monday to add a tool belt and two cameras that will serve as the robot's eyes as it helps maintain the station.
The robot, called Dextre, flew in pieces to the station aboard the shuttle Endeavour. It has been assembled over the course of three space walks.
So far, the 12-foot (3.7-meter) robot and both of its 11-foot (3.4-meter) arms have checked out fine.
On Tuesday evening, astronauts plan to use the International Space Station's mechanical arm to attach Dextre to the outside of the station's U.S. lab, Destiny.
"Making Rock Stars Question Their Job Choice"
The spacewalkers' robot-related chores went smoothly, but Behnken had some trouble attaching a science experiment to Europe's Columbus lab. He couldn't get the suitcase-sized experiment to latch firmly onto the platform.
Behnken ended up carrying the experiment back to Endeavour's payload bay, repeatedly expressing his disappointment.
"You gave it your all, Bob," Linnehan said. "No one could have done any better."
Experts on the ground will spend the next couple of days trying to figure out what's causing the problem and how to fix it or work around it.
Astronauts participating in one of the mission's final two space walks may end up tying down the experiment and its twin instead of bolting them, said Zebulon Scoville, the lead space walk officer for Endeavour's mission.
Despite the problem, Scoville said he couldn't have been more pleased with the spacewalkers' work.
"You're making rock stars question their job choice," Scoville radioed Behnken before asking him several questions about the troublesome fitting.
Five space walks were planned for Endeavour's 16-day flight, which is about halfway done. While shuttle astronauts have performed five space walks before on a single flight—on trips to the Hubble Space Telescope—it will be a record for a shuttle-station mission.
In addition to delivering Dextre to the space station, Endeavour's crew dropped off a storage compartment for the Japanese lab that will fly up in May.
The astronauts not involved with the space walks—including Japanese astronaut Takao Doi—continued setting up the storage compartment in preparation for the arrival of the lab, which is named Kibo—Japanese for hope.
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